• Journal of the Korean Vacuum Society
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• v.21 no.4
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• pp.205-211
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• 2012

We investigated the optical and hydrophobic properties of the deposited silver (Ag) zinc oxide (ZnO) nanorods (NRs) on flexible indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates (i.e., ITO/PET). The ZnO NRs were grown by an electrochemical deposition using a sputtered ZnO seed layer and the Ag was deposited by using a thermal evaporator. For comparison, the same fabrication process was carried out on the bare ITO/PET without ZnO NRAs. Due to the discrete surface of ZnO NRs, the deposited Ag was formed as nano-scale particles, while the Ag became film-like for bare ITO/PET. In order to control the size and amount of Ag particles, the Ag deposition time was changed from 100 to 600 s. When the deposition time was increased, the Ag particles became larger and denser, and the absorptance was increased. This enhanced absorptance may be due to the localized surface plasmon resonance of Ag particles. Furthermore, the relatively high hydrophobicity was observed for the deposited Ag on the ZnO NRs/ITO/PET. These improved optical and surface properties are expected to be useful for flexible photovoltaic and optoelectronic devices.

• Membrane Journal
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• v.19 no.4
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• pp.324-332
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• 2009

This study aimed to measure chemical resistance properties of the microfiltration flat-sheet membrane made by Chlorinated Polyvinyl Chloride (CPVC) with respect to the immersed time. The solutions of effective chlorine 0.5 wt% NaClO, HCl 1 wt% and pH 4 buffer under acidic condition, NaOH 4 wt% and pH 10 buffer under alkine condition were used as widely applied chemicals for membrane washing. The CPVC membrane samples were immersed in the above chemical solutions during 1, 3, 5 and 10 days at 5, 25 and $50^{\circ}C$, respectively. After then, the tensile strength and elongation at break as the chemical durability for the samples were measured and evaluated. The tensile strength decreased within 5% at $5^{\circ}C$, but decreased up to 17% at 25 and $50^{\circ}C$ for 0.5 wt% NaClO solution mainly used for membrane cleaning. The chemical resistance of CPVC membrane was good enough for HCl 1 wt% and pH 4 buffer acid solutions, but the most vulnerable for NaOH 4 wt% solution.

• Resources Recycling
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• v.30 no.5
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• pp.38-48
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• 2021

In this study, we determine the optimal process conditions for selectively recovering Si from a solar cell surface by removal of impurities (Al, Zn, Ag, etc.). To selectively recover Si from solar cells, leaching is performed using HCl solution and an ultrasonic cleaner. After leaching, the solar cells are washed using distilled water and dried in an oven. Decompression filtration is performed on the HCl solution, and ICP-OES (Inductively Coupled Plasma Optical Emission spectroscopy) full scan analysis is performed on the filtered solution. Furthermore, XRD (X-ray powder diffraction), XRF (X-ray fluorescence), and ICP-OES are performed on the dried solar cells after crushing, and the purity and recovery rate of Si are obtained. In this experiment, the concentration of acid solution, reaction temperature, reaction time, and ultrasonic intensity are considered as variables. The results show that the optimal process conditions for the selective recovery of Si from the solar cells are as follows: the concentration of acid solution = 3 M HCl, reaction temperature = 60℃, reaction time = 120 min, and ultrasonic intensity = 150 W. Further, the Si purity and recovery rate are 99.85 and 99.24%, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.393-402
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• 2020

In the membrane process, it is important to improve water treatment efficiency to ensure water quality and minimize membrane fouling. In this study, a pilot study of membrane process using reservoir water was conducted for a long time to secure high flux operation technology capable of responding to influent turbidity changes. The raw water and DAF(Dissolved Air Flotation) treated water were used for influent water of membrane to analyze the effect of water quality on the TMP (Trans Membrane Pressure) and to optimize the membrane operation. When the membrane flux were operated at 70 LMH and 80 LMH under stable water quality conditions with an inlet turbidity of 10 NTU or less, the TMP increase rates were 0.28 and 0.24 kPa/d, respectively, with minor difference. When the membrane with high flux of 80 LMH was operated for a long time under inlet turbidity of 10 NTU or more, the TMP increase rate showed the maximum of 43.5 kPa/d. However, when the CEB(Chemically Enhanced Backwash) cycle was changed from 7 to 1 day, it was confirmed that the TMP increase rate was stable to 0.23 kPa/d. As a result of applying pre-treatment process(DAF) on unstability water quality conditions, it was confirmed that the TMP rise rates differed by 0.17 and 0.64 kPa/d according to the optimization of the coagulant injection. When combined with coagulation pretreatment, it was thought that the balance with the membrane process was more important than the emphasis on efficiency of the pretreatment process. It was considered that stable TMP can be maintained by optimizing the cleaning conditions when the stable or unstable water quality even in the high flux operation on membrane process.

• Korean Journal of Child Education & Care
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• v.18 no.2
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• pp.85-102
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• 2018

The purpose of this study is to determine the working conditions and demands of the assistant workforce at childcare centers, and to provide suggestions on policies for childcare teachers. To achieve the purpose of the study, a total of 190 assistant teachers, nursing helpers, alternative teachers and others were surveyed online during the month of August 2017. The survey examined the employment route and working motives, working conditions and environment, job and educational difficulties for analyzing the work conditions and demands of ancillary staff. For the analysis method, SPSS 12.0 was used to analyze frequency and difference. The main findings are as follows. First, childcare center assistants were able to work at their respective times, making it mandatory for them to enter the workforce, and making job openings for ancillary teachers. Second, 73.7% said the daily working hours were '4 hours to 8 hours' under the conditions and 57.9% said 'More than 510,000 won to less than 1 million won.' Average amount of rest time per day was about 30 minutes, and 17% had no rest periods. Third, based on the job and education status, ancillary personnel performed "infant and child guidance and interaction", "Cleaning and cleanliness related tasks" most actively, and "care for cleaning and cleanliness" and "care for morning and night care". Fourth, in the job trouble and difficulty, ancillary staff found it difficult to satisfy with wage related complaints and job insecurity, and the reason for agreeing to the non-regular workforce becoming a regular worker was found to be due to the stability of employment. Lastly, the most urgent tasks to solve the problem of non-regular workers were to fill the wage gap between regular and irregular workers, shorten the working hours and improve the working conditions. The policy implications are presented based on the above findings.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.310-316
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• 2022

In this study, we compared the microbial reduction effects of drying, hot water, and microwave sterilization in scourers and dishcloths to suggest a most suitable sterilization method. Three scourer types (silver, copper, and mesh) were used, and three dishcloth types (silver, bamboo, and cotton) were used. Drying time dependent reduction in Escherichia coli was high in silver and copper scourers, but minimal bacterial reduction was obtained against Bacillus cereus in all scourers and dishcloths. In scourers, E. coli was not detected after ≥30 s of hot water sterilization at 77℃, and B. cereus was not detected after ≥60 s of hot water sterilization at 100℃. In dishcloths, E. coli was not detected after hot water sterilization at 77℃ for ≥30 s, but B. cereus was detected after hot water sterilization at 100℃ for ≥60 s. In scourers, E. coli was not detected after microwave sterilization at 700 W for 3 min, but B. cereus was detected. In dishcloths, E. coli was not detected after microwave sterilization with 700 W for ≥1 min, but B. cereus was detected in the cotton dishcloth even after sterilization for 3 min. In conclusion, the use of antimicrobial scourers (silver and copper) and dishcloths (silver and bamboo) are not sufficient to reduce the microbial contamination. The guideline provided by the Ministry of Food and Drug Safety suggesting dishcloth sterilization via hot water at 100℃ for 30 s was also found to be insufficient. Based on our research, we suggest that the most effective methods of microbial management are submerging scourers in hot water at 100℃ for ≥1 min, and sterilizing dishcloths for ≥3 min using a 700 W microwave.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.45-53
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• 2015

These days Container Terminals are focusing on increasing the quantity of containers and shipping lines choose Terminals by referring to the key elements of a terminal to perform the overall operation the fastest such as the location of the terminal, discharging ability, keeping environment, and other elements related to shipping in general. Container terminal is able to offer On-Dock service has become an important factor for shipping lines to choose that terminal. In this paper, we propose an algorithm for On-Dock system work algorithm, the algorithm Empty container exports, Full Container algorithm and The aim of our study focus on both container's gate out time and search for the effective terminal operation which is using the general On-Dock system through several algorithm like container batch priority, gate in and out job priority and empty container yard equipment allocation rule based on the automatic allocation method and manual allocation scheme for container. Gathering these information, it gives the priority and yard location of gate-out containers to control. That is, by selecting an optimum algorithm container, container terminals Empty reduces the container taken out time, it is possible to minimize unnecessary re-handling of the yard container can be enhanced with respect to the efficiency of the equipment. Operations and operating results of the Non On-Dock and On-Dock system is operated by the out work operations (scenarios) forms that are operating in the real Gwangyang Container Terminal derived results. Gwangyang Container terminal and apply the On-Dock system, Non On-Dock can be taken out this time, about 5 minutes more quickly when applying the system. when managing export orders for berths where On-Dock service is needed, ball containers are allocated and for import cargoes, D/O is managed and after carryout, return management, container damage, cleaning, fixing and controlling services are supported hence the berth service can be strengthened and container terminal business can grow.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.4
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• pp.412-421
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• 2012

The yerba mate that grows in the subtropical forests of South America is an evergreen tree within the Aquifoliaceae family. The yerba mate (Ilex paraguariensis) tea is habitually used as a drink in Argentina, Paraguay, Uruguay, and Southern Brazil. A wild mate tree needs about 25 years to fully grow to 15 a height of meters; however, they only grow to a height of 3-5 meters when cultivated. The leaves are 7-11 cm long and 3-5cm wide with a serrated margin. Yerba mate tea-based beverages are made from the leaves and stems of the mate tree. It is known that they contain a rich content of antioxidants and polyphenol, vitamins, amino acids, minerals and colorants. Dyeing properties of a mate plant in the silk, wool, linen and cotton fabrics were investigated. Constituents of colorant of mate tea are chlorophyll and carotinoid; in addition, it has more minerals such as (Fe, Ca, Mn, Mg, Na, K, Zn, and Cu) than green tea. Mate tea colorants showed good affinity to silk and wool fabrics. It was found that the optimum condition for dyeing was 30 minutes for dyeing time, 7 for pH of dyebath, and at a dyeing temperature of $80^{\circ}C$. The maximum absorbance wavelength (${\lambda}_{max}$) of silk and wool fabrics dyed with mate tea were at 420-440nm; however, that of linen and cotton fabrics were at 400nm. K/S values of fabrics dyed under optimum conditions were 1.979 for silk fabrics, 1.541 for wool fabrics, 0.551 for linens and 0.465 for cotton fabrics. Munsell hue values of dyed fabrics measured 3.1Y-6.4GY for silk, 1.4Y-8.3Y for wool, 5.5Y-3.7GY for linen, and 5.3Y-1.3GY for cotton. All dyed fabrics showed hues in-between greenish yellow and greenyellow. Colorfastness to rubbing, perspiration and dry-cleaning of dyed fabrics with mate tea were very good; however, the grades of colorfastness to washing of dyed linen and cotton fabrics were poor, and colorfastness to light were poor.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7205-7210
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• 2015

Background: In this study, influence caused by expression plasmids of connective tissue growth factor (CTGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1) short hairpin RNA (shRNA) on mRNA expression of CTGF,TIMP-1,procol-${\alpha}1$ and PCIII in hepatic tissue with hepatic fibrosis, a precancerous condition, in rats is analyzed. Materials and Methods: To screen and construct shRNA expression plasimid which effectively interferes RNA targets of CTGF and TIMP-1 in rats. 50 cleaning Wistar male rats are allocated randomly at 5 different groups after precancerous fibrosis models and then injection of shRNA expression plasimids. Plasmid psiRNA-GFP-Com (CTGF and TIMP-1 included), psiRNA-GFP-CTGF, psiRNA-GFP-TIMP-1 and psiRNA-DUO-GFPzeo of blank plasmid are injected at group A, B, C and D, respectively, and as model control group that none plasimid is injected at group E. In 2 weeks after last injection, to hepatic tissue at different groups, protein expression of CTGF, TIMP-1, procol-${\alpha}1$ and PC III is tested by immunohistochemical method and,mRNA expression of CTGF,TIMP-1,procol-${\alpha}1$ and PCIII is measured by real-time PCR. One-way ANOVA is used to comparison between-groups. Results: Compared with model group, there is no obvious difference of mRNA expression among CTGF,TIMP-1,procol-${\alpha}1$, PC III and of protein expression among CTGF, TIMP-1, procol-${\alpha}1$, PC III in hepatic tissue at group injected with blank plasmid. Expression quantity of mRNA of CTGF, TIMP-1, procol-${\alpha}1$ and PCIII at group A, B and C decreases, protein expression of CTGF, TIMP-1, procol-${\alpha}1$, PC III in hepatic tissue is lower, where the inhibition of combination RNA interference group (group A) on procol-${\alpha}1$ mRNA transcription and procol-${\alpha}1$ protein expression is superior to that of single interference group (group B and C) (P<0.01 or P<0.05). Conclusions: RNA interference on CTGF and/or TIMP-1 is obviously a inhibiting factor for mRNA and protein expression of CTGF, TIMP-1, procol-${\alpha}1$ and PCIII. Combination RNA interference on genes of CTGF and TIMP-1 is superior to that of single RNA interference, and this could be a contribution for prevention of precancerous condition.

• Journal of dental hygiene science
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• v.17 no.1
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• pp.73-80
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• 2017

Periodontal diseases occur from the interplay between increased bacterial response and the response of the host immune system over time. Anxiety and depression can impair immunological defense mechanisms, causing accumulation of periodontopathogens and thus exacerbating periodontal disease. We investigated the relationship of anxiety and depression to periodontal diseases in Korean women. In this study, 3,551 women aged ${\geq}19$ years were evaluated based on data from the first year (2010) of the Fifth Korea National Health and Nutrition Examination Survey. The analysis of the factors that caused periodontal diseases revealed that dental floss or interdental toothbrush nonuse behaviors have been shown to increase the risk of periodontal disease (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.14~1.95). After adjusting for conditions such as age, marital status, income, educational level, economic activity, diabetes mellitus, smoking, drinking, and frequencies of toothbrushing and interdental cleaning, we found that anxiety and depression increased the risk of developing periodontal diseases (OR, 1.47; 95% CI, 1.04~2.09). People with anxiety and depression have a higher prevalence of periodontal diseases than people without anxiety and depression. Thus, periodic periodontal care and effective self-care education are needed to manage periodontal diseases.